Optical recording/playback of information has been made possible by developments in the areas of lasers and thermal record media. Recent developments have led to mass data storage systems utilizing a plurality of individually modulated laser beams to record information at extremely high data rates. For example, in U.S. Pat. No. 4,449,212 issued on May 5, 1984, in the name of the instant inventor, a multi-track record/playback apparatus is described. In the multi-track apparatus the light beam from a single high power laser is split into a plurality of beams which are individually modulated and focused onto the surface of a record medium. In general, systems of this type require large, high power lasers which require external cooling. Furthermore, in these systems a modulator is provided to individually modulate each beam of the multiple beams being used for recording. For these reasons, prior art multi-beam systems tend to be bulky, low in efficiency, and difficult to modulate.
The development of semiconductor laser arrays is the first step to multi-channel optical recorders/players which overcome some of the problems of the prior art multi-channel systems. A diode laser array system is generally more compact, has higher efficiency, and requires no external modulation.